Plant Soil Environ., 2018, 64(9):441-447 | DOI: 10.17221/313/2018-PSE

Four soil phosphorus (P) tests evaluated by plant P uptake and P balancing in the Ultuna long-term field experimentOriginal Paper

Klaus A. JAROSCH^*,1,4, Jakob SANTNER^2,3, Mohammed Masud PARVAGE⁴, Martin Hubert GERZABEK², Franz ZEHETNER², Holger KIRCHMANN⁴

¹ Group of Soil Science, Geographical Institute, University Bern, Bern, Switzerland

² Instituteof Soil Research, Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences Vienna, Vienna, Austria

³ Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences Vienna, Tulln, Austria

⁴ Department of Soil and Environment, Swedish University of Agricultural Sciences,

Soil phosphorus (P) availability was assessed with four different soil P tests on seven soils of the Ultuna long-term field experiment (Sweden). These four soil P tests were (1) P-H₂O (water extractable P); (2) P-H₂O_C10 (water extractable P upon 10 consecutive extractions); (3) P-AL (ammonium lactate extractable P) and (4) P-C_DGT (P desorbable using diffusive gradients in thin films). The suitability of these soil P tests to predict P availability was assessed by correlation with plant P uptake (mean of preceding 11 years) and soil P balancing (input vs. output on plot level for a period of 54 years). The ability to predict these parameters was in the order P-H₂O_C10 > P-C_DGT > P-H₂O > P-AL. Thus, methods considering the P-resupply from the soil solid phase to soil solution performed clearly better than equilibrium-based extractions. Our findings suggest that the P-AL test, commonly used for P-fertilizer recommendations in Sweden, could not predict plant P uptake and the soil P balance in a satisfying way in the analysed soils.

Keywords: soil testing; macronutrient; phosphorus desorption; nutrition; fertilization; saturation index

Published: September 30, 2018  Show citation